Hitherto, there is known a drive assisting device that is mounted on a vehicle and outputs information for assisting a driver's operation of driving the vehicle. As such a drive assisting device, for example, Patent Literature 1 discloses a device that notifies a timing at which the vehicle needs to be decelerated to the driver when the vehicle needs to be stopped with respect to a traffic light based on the time at which the vehicle reaches the traffic light and the time at which a signaling lamp color changes.